21841974 has 160 divisors (see below), whose sum is σ = 65235456. Its totient is φ = 5287680.

The previous prime is 21841913. The next prime is 21842021. The reversal of 21841974 is 47914812.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 212007 + ... + 212109.

Almost surely, 2^21841974 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21841974, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32617728).

21841974 is an abundant number, since it is smaller than the sum of its proper divisors (43393482).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21841974 is a wasteful number, since it uses less digits than its factorization.

21841974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152 (or 143 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 21841974 is about 4673.5397719502. The cubic root of 21841974 is about 279.5314186452.

The spelling of 21841974 in words is "twenty-one million, eight hundred forty-one thousand, nine hundred seventy-four".